1. Field of the Invention
The present invention relates to a polycarbonate resin composition, and more particularly to a polycarbonate resin which has an improved fluidability and solvent resistance in addition to the mechanical properties of conventional polycarbonate resin compositions, and is excellent in moldability, particularly in blow moldability.
2. Description of the Related Arts
Processes for production of polycarbonate using phloroglucine or trimellitic acid as a branching agent have heretofore been known, as disclosed in for example, Japanese Patent Publication Nos. 17149/1969, and 11733/1985. Use of these branching agents, however, suffers from a disadvantage in that a trace amount of unreacted matter is apt to cause coloring.
In Japanese Patent Application Laid-Open No. 45318/1984, 1,1,1-tris(4-hydroxyphenyl)ethans is proposed to be used as a branching agent. However, the specification of U.S. Pat. No. 4,415,723 discloses that the polymer obtained by using this branching agent is colored to pals yellowish green in Comparative Example A, and suggests the use of a branching agent such as 1,1,2-tris(4-hydroxyphanyl)ethans and 1,1,2-tris(4-hydroxyphenyl)propane. Yet the process disclosed in the above U.S. Pat. No. 4,415,723 cannot completely solve the problems of coloring.
It is known that when a polycarbonate is branched for blow molding, its impact resistance decreases. Accordingly, development of a branched polycarbonate with high impact resistance had been required.
The present inventors' group had investigated from such points of view, and succeeded in solving the problem of hue to develop a branched polycarbonate suitable for blow molding which have acetone-soluble matter of not more than 3.5% by weight and an improved impact-strength (Japanese Patent Application Laid-open No. 182524/1991).